Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and a rotor having a rotatable hub with one or more rotor blades. The rotor blades capture kinetic energy of wind using known airfoil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
The wind turbine tower can account for up to 40% of its cost. As such, to reduce wind turbines costs, a lighter tower design having increased tower reliability is preferred. In such towers, however, it is critical to know when tower loads are near the design limit, i.e. by estimating tower deflection since wind turbine towers are analogous to springs. Conventional estimation approaches include estimating a slowly varying thrust from which steady-state tower deflection can be inferred.
However, more accurate estimation approaches would be desirable.